The development of renewable and environmentally benign energy sources has emerged as one of the most pressing challenges of the 21st century. It has been estimated that increases in world population coupled with the rise of emerging economies will produce an increase in energy consumption from 13 TW today to 30 TW by 2050 (Lewis et al., Proceedings of the National Academy of Sciences (2006) 103:15729). Given that 86% of this energy comes from fossil fuels, and that CO2 levels are currently the highest they have been for the past 650,000 years, it is clear that the burn rate that will be needed to sustain future energy requirements is unacceptable (Herrero et al., Coordination Chemistry Reviews (2008) 252:456-468).
Natural photosynthesis converts solar energy into chemical energy in a non-toxic and highly efficient manner, and has thus been studied for decades as a model for the creation of photo-induced renewable energy devices. During photosynthesis, absorption of light by phototrophic organisms initiates a series of electron transfer reactions that lead to the production of carbohydrates upon reduction of CO2 and the oxidation of H2O to O2. The photosynthetic process can be described by the following formulae:2H2O+4hv→O2+4H++4e−nCO2+2ne−+2nH+→(CH2O)n 2H++2e−→H2 
The photosynthetic protein apparatus, which is a complex array of several membrane-bound proteins, self-assembles, absorbs most of the solar spectrum, and has a quantum efficiency of greater than 98% conversion of photon energy to the desired reaction products. Artificial photosynthesis thus aims to harness energy from electron transfer events to drive the production of high energetic fuels such as H2 and reduced forms of carbon (Hay et al., Proceedings of the National Academy of Sciences (2004) 101:17675-17680).
Bio-inspired systems linking organic molecules to synthetic matrix scaffolds have strived to recreate individual elements of the photosynthetic apparatus (Fukuzumi et al., Bulletin Of The Chemical Society Of Japan (2006) 79:177-195; Kodis, G., Terazono et al., J Am Chem Soc (2006) 128:1818-1827). These “integrated modular assemblies” have provided a basis for constructing molecular devices fashioned on nanoscale materials which position the active elements at fixed distances to transform photonic energy into vectorial electron transfer (Alstrum-Acevedo et al., Inorganic Chemistry (2005) 44:6802-6827; Meyer, et al. Accounts Of Chemical Research (1989) 22:163-170). However, the synthetic-based systems that have been constructed to date are expensive to prepare, synthetically challenging, and their production is often damaging to the environment (Coakley et al., Chemistry Of Materials (2004) 16:4533-4542). For these reasons, the prior art constructs are not feasible for commercial application.
Hence there is a pressing need for a simple, robust solar energy conversion device with the scale and complexity of natural systems, such as the photosynthetic reaction center, that can be constructed in an efficient, environmentally friendly, and cost effective manner.